Self-loading skidder and stacker



Sept 19, 1967 R. w. LARSON 3,342,357

SELF-LOADING SKIDDER AND STACKER Sept 19, 1957 R. w. LARSON 3,342,357

SELF-LOADING SKIDDER AND STACKER Filed Oct. 13, 1965 5 SheetS-Sheei 2FIC-325 i vliiw/ f fm. Raaf/e7 M r9/vso r roza/frs Sept 19, 1967 R. w.LARSON 3,342,357

SELF-LOADING SKIDDER AND STACKER Filed Oct. 13, 1965 35 Sheets-Sheet 552? o 80 X H \I\\\\\\\\\\\\Q\ v V/N '1 ok. A705527' M meson mmv/frrokneys United States Patent C 3,342,357 SELF-LOADING SKIDDER ANDSTACKER Robert W. Larson, Ashland, Wis., assignor to Beloit Corporation,Beloit, Wis., a corporation of Wisconsin Filed Set. 13, 1965, Ser. No.495,387 1 Claim. (Cl. 214-147) This invention relates to a self-loadinglog handling vehicle having an improved boom and grapple mechanism. Moreparticularly, the invention relates to a highly maneuverable loghandling vehicle capable of eiliciently skidding a bunch of logs fromone location to another and stacking the bunch when desired.

In modern logging operations, it is often necessary to transport logsover substantial distances from the place where they are cut to anotherplace in the forest over terrain which is impassable to conventionalvehicles such as trucks and the like. Special vehicles called skiddersare ordinarily used to move the logs to a place which can be reached byconventional vehicles, and at that location, the logs are either loadedfor transport to the mill or are placed on storage stacks until they areneeded.

It is an object of this invention to provide a log handling vehiclehaving a high degree of maneuverability and being capable of loadingitself with a hunch of logs from a temporary storage stack or windrow,skidding the hunch to a second location, and there loading the buncheither directly on a truck or the like or on another stack.

It is another object of the invention to provide a log manipulatingmachine having a hydraulically actuated heel boom arrangement which iscapable of a wide range of movement so that logs can be skidded andloaded more quickly and easily, and thus more economically, than withprior art log handling machines.

It is still another object of the invention to provide a novel boomarrangement for a log handling vehicle which can be extended to pick upa bunch of logs from the ground and retracted to draw the end of thebunch of logs up over the vehicle to place the load squarely thereon forskidding and to bring the load closer to the vehicle when the logs arepicked up completely in a stacking operation.

Other objects, advantages and new features of the invention will becomeapparent from a reading of the following detailed description, inconjunction with the accompanying drawings in which:

FIGURE 1 is a side elevational view of a preferred embodiment of a loghandling machine according to the present invention showing, in phantomoutline, some alternative positions of the boom and grapple structure;

FIGURE 2 is a top plan view of the present log handling machine;

FIGURE 3 is a front elevational view of the machine with the log grappleshown in solid lines in the skidding or stacking positions thereof, andin phantom outline in the self-loading position;

FIGURE 4 is a side elevation showing the grapple in position to engage abunch of logs on the ground;

FIGURE 5 is a view similar to FIGURE 4 but showing the machine with itsboom in the skidding position; and

FIGURE 6 is a similar view showing the parts in their stacking relation.

In the illustrated embodiment of the invention, the log handling vehicleis generally designated by reference numeral 10 throughout the severalviews. Vehicle 10 is articulated so that it is quite maneuverablethrough the woods and consists of a forward two-wheeled tractor p ortion11 and a rearward two-wheeled trailer portion 12, pivotally connectedtogether as generally indicated at 13. It will be understood that thetractor portion 11 carries a suitable engine for driving the frontWheels 14 for propel- 3,342,357 Patented Sept. 19, 1967 ice ling themachine and for powering the hydraulicV equipment on the trailer 12.

Trailer 12 has a pair of rear wheels 15 journaled in suitable supports16 and 18 fixed to the frame 19 of trailer 12. It will be noted inFIGURE 2 that frame 19 is recessed or cut back as indicated at 20 sothat the wheels 15 may be brought into straddling relation to a bunch oflogs. A transverse brace 24 may also form part of frame 19.

For carrying out the log handling functions of the machine, a boom andgrapple structure 27 is mounted on trailer 12. Structure 27 includes amain boom frame 28, mounted on trailer 12 for rotation about ahorizontal axis. Main boom frame 28 has a right boom leg 30 pivotallyattached by means of a pin 31 to a lug 32 ixed to wheel support 18 asseen in FIGURE l and a parallel left boom leg 34 is attached in the samemanner by a pin and lug 32' (FIG. 2) to wheel support 16. Boom legs 30and 34 are transversely joined and braced as by transverse beams 38 andbraces 39 to complete the structure of main boom frame 28.

A pair of double acting hydraulic motors 40 and 42 of conventionalstructure are provided to move main boom frame 28 about the axis of itssupporting pins. Here, as elsewhere, the hydraulic lines to the motorshave been omitted for clarity. As shown in FIGURE 1, hydraulic motor 40has its cylinder 43 pivotally anchored by means of a pin 44 on asuitable lug 46 secured to frame 19. The extension rod 47 of motor 46 ispivotally attached to boom leg 30 by means of a pin 48 and a lug 49 onone of the transverse beams 38. Motor 42 is similarly connected on theleft side of the machine so that simultaneous actuation of motors 40 and42 will swing main boom frame 28 about its horizontal axis. It will benoted in FIGURE 1 that the anchor point for the hydraulic motors islocated well to the left of the pivot axis of main boom frame 28, andthat this is on the opposite side from the working side of the boom andgrapple structure 27. It will be noted further that the parts have beendimensioned and shaped such that the free end 51 of main boom frame 28may be brought well to the left of the axis of the rear wheels 15 of themachine when the motors 4t) and 42 are fully retracted. As will appearmore fully hereinafter, this arrangement will bring the rear ends of thelogs well forward of the rear wheels 15 so that the logs may be easilyhandled, both in the skidding and in the stacking operations.

Pivotally connected by means of a suitable pin 50 to the free end 51 ofthe main boom frame 28 is a heel boom frame 52 consisting of left andright parallel heel boom legs 54 and 55 respectively, and a transverserod 58 near the free end 65 of heel boom frame 52. Double actinghydraulic motors 63 and 64 are connected between main boom frame 28 andheel boom frame 52 for moving the latter around its pivot 50, as shown.When motors 4t) and 42 and 63 and 64 are fully extended, the parts willbe in the full reach position shown in phantom outline in FIGURE 1 withthe heel boom frame extending out of the figure to the right. It will beapparent that a large range of vertical movement of the free end 65 ofheel boom frame 52 is possible with the present linkage. Since the heelboom legs 54 and 55 must support a high -bending moment-around theconnection point of motors 63 and 64, spine braces 60 and 62 arepreferably used on the upper edges thereof.

A log grapple 66 is pivotally attached in pendulous fashion on thetransverse rod 5S near the free end 65 of heel boom frame 52. This loggrapple may take any convenient form, but is preferably a hydraulicallyactuated grapple having opposed jaws 68 and 69 pivoted -on a supportblock 70. Double acting hydraulic motors 71 3 and 72 act between theblock 70 and the jaws 68 and 69 for moving the same between their openand closed positions, the open position being shown in phantom outlinein FIGURE 3.

The boom and grapple structure also includes a cradle unit 73 consistingof longitudinal ribs 74 and transverse ribs 75 secured together in theconfiguration shown. The cradle unit is pivotally attached to the heelboom frame 52 near the free end 65 thereof as by means of a transverserod 77 and a lug 78 xed to heel boom leg 54. It will be understood thata similar lug connects the cradle unit 73 to the other heel boom leg 55.A pair of hydraulic motors 80 and 81 are connected between heel boomframe 52 and cradle unit 73 to pivot the latter about the axis definedby pin 77. l

FIGURES 4, 5 and 6 illustrate the operation of the present machine.Referring first to FIGURE 4, the machine is there shown as having beenpositioned at the end of a stack of logs 85 and with the boom andgrapple extended into position to grasp the logs. This is presumablybeing done at a cutting or felling location where the logs would havebeen previously placed in temporary storage stacks. The operation shownin FIGURE 4 may be carried out by actuating motors 40 and 42 alone, orby actuating these motors in combination with motors 63 and 64 to varythe reach of the assembly as desired. The grapple structure will remainvertically oriented because of the pendulous nature thereof. Moreover,the wheels 15 may straddle the end of the stack because of the recessedconstruction of trailer frame 19. The grapple jaws are then closed tohold the stack.

To load the stack for the skidding operation, motors 40 and 42 areretracted to swing the entire assembly to the left around the axis ofpins 31 and 35. This action will lift the end of the stack olf theground and will draw the entire stack toward the machine, positioningthe end of the stack well forward of the axis of the rear wheels 15. Itwill be understood that motors 63 and 64 may be utilized at the sametime to assist in the lifting operation and to insure that the end ofthe stack will clear the frame 19 as the stack rises to the loadedposition. The parts will then occupy the positions shown in FIGURE 5,and the vehicle may be propelled forward to drag or skid the logs toanother location in the forest. It will be appreciated that thearrangement of main boom frame 28 and its motors 40 and 42 is such thata portion of the load is placed on the vehicle well forward of the rearwheels, providing for stability during the skidding operation.

When the vehicle with its load of logs reaches its destination, cradleunit 73 may be brought into play to assist in the placing of the logsonto a storage stack or onto a truck or the like, as shown in FIGURE 6.In carrying out the stacking operation, motors 80 and 81 are operated tolower cradle unit 73 into engagement with the heel of the stack. All ofthe hydraulic motors may then be 0perated to lift the stack into thehorizontal and to move it to any desired vertical position. Theavailable range of vertical movement is quite high ydue to thearrangement of the boom elements. The vehicle will then be propelledtoward the stack or truck and the logs can then be lowered into place byoperation of the hydraulic motors. It will be understood that the weightof the tractor portion 11 will be sufficient to oiset the moment aboutthe rear axis which is produced 'by the logs during this operation.

It should be apparent that the vehicle as herein described fully meetsthe objectives of the invention set forth above. Only one operator isrequired and the handling of logs through the skidding and stackingoperations can be carried out quickly and efficiently by this machine.

Since various changes in form, details and proportions will occur tothose skilled in the art when they are provided with the benefit of thepresent disclosure, it will be understood that within the scope of theappended claims, the invention may be practiced otherwise than as hereinspecifically described.

l claim:

An improved self-loading skidder and stacker for hunched logs comprisinga vehicle adapted to be propelled along the ground, a main boom framepivotally mounted on said vehicle near one end thereof, hydraulic motormeans connected between said vehicle and said main boom frame, one endof said hydraulic motor means being pivotally connected to said vehicleat a point spaced farther from said one end of said vehicle than thepivot point of said main boom frame, the other end of said hydraulicmotor means being pivotally connected to said main boom frameintermediate the ends thereof, said hydraulic motor means in the fullyretracted condition thereof positioning the free end of said main boomframe between the ends of said vehicle, and in the fully extendedcondition thereof positioning the free end of said main boom framebeyond said one end of said vehicle, a heel boom frame pivotallyconnected to the free end of said main boom frame for rotation about ahorizontal axis, hydraulic motor means connected -between said main boomframe and said heel boom frame for moving said heel boom lframe aboutits axis, a log grapple pivotally mounted on said heel boom frame at thefree end thereof, a cradle unit pivotally carried on said heel boomframe intermediate the ends of said heel boom frame and having a portionthereof movable in a generally vertical path to engage the heel end of abunch of logs clamped in said grapple and for forcibly pivoting saidbunch of logs about the pivot axis of said grapple, the pivot for saidcradle unit being closely adjacent the pivot of said log grapple, saidsubstantially vertical path having a proximal relationship with saidmain boom frame when the free end of said main boom frame residesbetween the ends of said vehicle and said generally vertical path beingbetween the pivot locus of said main boom frame and the free end of saidmain boom frame when said free end resides between the ends of saidvehicle, and hydraulic motor means connected between said heel boomframe and said cradle unit for causing said engaging portion of thecradle unit to eiect said engagement with the heel end of the bunch oflogs, whereby to heel said bunch of logs requires that a sufficientlength thereof resides between said grapple and the said substantiallyvertical path with the consequence that the heeling action provided bysaid cradle unit takes place at an optimum location between the ends ofsaid vehicle.

References Cited UNITED STATES PATENTS 891,385 6/1908 Strange 214-3942,754,016 7/1956 Anderson 214-147 2,903,146 9/1959 Meloy 214--1473,079,020 2/ 1963 Gustine 214-147 3,165,215 1/1965 Larson 214--147 HUGOO. SCHULZ, Primary Examiner.

